Chronic dry eye is a most common condition encountered in the clinics by Ophthalmologists. It is known to increase with age and is more commonly detected in women. Prevalence of chronic dry eye in some studies is reported at approximately 5 million people>50 years of age in the U.S. and in others to 23 million Americans. It is also a very common condition that develops after refractive surgery. More recently dry eye has been associated with inflammation. However current treatments are primarily palliative approaches while topical application of anti-inflammatory drugs such as steroids and Cyclosporin A (CsA) have met with limited success. In a mouse model where dry eye is induced by exposing animals to desiccating environment with low humidity, development of inflammatory immune response is reported that resembles what is typically seen in autoimmune conditions (Stevenson W, et al. Dry Eye Disease: An Immune-Mediated Ocular Surface Disorder. Arch Ophthalmol. 2012; 130 (1):90-100). Such studies imply that development of dry eye could potentially initiate a chronic inflammatory condition that requires long-term treatment.
Dry eye that develops after refractive surgery, besides causing ocular discomfort may also increase susceptibility to bacterial infections and risk of chronic disease development. A genetic biomarker could serve as a useful tool for the stratification of dry eye disease. Clinical categorization of patients at risk of developing dry eye can help establish the need for a follow on treatment. Biomarkers may also be used as prognostics to improve pharmacodynamics and safety testing for a pre-clinical or clinical phase of drug development.